1. Field of the Invention
The present invention relates to a sensor cleaning mechanism, and more particularly to a cleaning mechanism arranged on a function unit that is detachable with respect to a main body of an image forming device, and which serves to clean a photosensor mounted on the function unit.
In addition, the present invention relates to a sensor cleaning control device, and more particularly to a photosensor cleaning control device of an image forming device having a function unit that is detachable with respect to a main body of the image forming device, and which cleans a photosensor by means of a cleaning mechanism that uses the act of installing and removing the function unit.
2. Background Information
A photosensor is arranged in an image forming device such as a copying machine, printer, and the like in order to detect image density, registration, and the like. This photosensor is either arranged on the main body of the image forming device, or is arranged on a unit that is detachably mounted on the main body of the image forming device.
This type of photosensor includes a translucent detection surface, but if toner or other foreign matter becomes adhered to the detection surface, detectability will deteriorate, normal detection values will no longer be obtained, and thus accurate control can no longer be performed.
Accordingly, mechanisms for cleaning the detection surface of photosensors have been proposed in the past. For example, in the device shown in Japanese Unexamined Patent Application No. H06-3878, a photosensitive unit, an electrostatic charger, a developer and a cleaner are unitized to form a process cartridge, and this process cartridge is detachable with respect to the main body of the device. A photosensor that detects the toner density on the photosensitive unit is installed on the main body of the device, and when the process cartridge is installed or removed, a cleaning member that is attached to the casing of the process cartridge will come into contact with the surface of the photosensor so as to clean the surface thereof.
Conventional photosensor cleaning mechanisms are designed to clean a photosensor attached to the main body of a device with a cleaning member arranged on a unit that is detachable with respect to the main body of the device. In other words, the photosensor is arranged on a fixed main body of the device, and the cleaning member is arranged on a movable unit.
However, when the photosensor is disposed in the rear of the device main body, the cleaning member on the unit may not come into contact with the photosensor when installing or removing the unit due to the position in which the photosensor is disposed. In addition, in order to bring the photosensor into contact with the cleaning member, it will be necessary to handle the device main body and the unit will a high decree of precision when the unit is installed in or removed from the device main body, and the guide members used to install and remove the unit must be highly precise so that there is no play when the unit is installed or removed.
Furthermore, the situation described above is also true with the reverse configuration, in which the photosensor is installed on the detachable unit. In other words, when the photosensor is disposed on the rear of the unit, the cleaning member arranged on the device main body cannot come into contact with the photosensor. In addition, the positional relationship of both must be managed with a high degree of precision.
In the conventional mechanisms described above, in which the photosensor and the cleaning member are arranged on a fixed portion (the device main body) and a movable portion (the unit), and which clean the surface of the photosensor by bringing the photosensor and the cleaning member into contact with each other when the movable portion is installed and removed, cleaning may not be performed due to the position of the photosensor, and the positional relationship of the photosensor and the cleaning member must be managed with a high degree of precision.
In addition, the photosensor cleaning mechanism disclosed in the prior art reference noted above is designed to clean the surface of the photosensor when the process cartridge is installed or removed. Because of this, the surface of the photosensor will not be cleaned so long as the process cartridge is not installed or removed. One could install and remove the process cartridge periodically in order to clean the process cartridge. However this type of task is easy to forget, and thus the surface of the photosensor may not be cleaned for a long period of time, and accurate control of the image forming device will not be possible.
In addition, the installation and removal of a function unit such as the process cartridge is normally carried out when a paper jam occurs near the function unit. However, because image forming devices are designed so that paper jams occur as infrequently as possible, the installation and removal of the function unit may not occur for a long period of time.